1. Field of the Invention
The present invention relates to a throttle device for a vehicle such as a motorcycle.
2. Description of Background Art
Conventionally, a throttle device is known wherein the turning amount of a throttle grip is detected by use of a magnetic sensor. See, for example, Japanese Patent Laid-open No. 2005-194925. This throttle device has a configuration wherein the throttle grip is provided, at the outer periphery on the handle base end side thereof, with a projecting part for holding a magnet of the magnetic sensor, a housing (switch box) for containing and holding the handle base end side of the throttle grip is provided with a sensor body (Hall sensor) of the magnetic sensor, and the projecting part and the sensor body are opposed to each other in a radial direction of a handle bar.
In the conventional configuration as above-mentioned, the projecting part at the outer periphery of the throttle grip and the sensor body on the housing side are opposed to each other in a radial direction of the handle bar, so that the housing for containing these components tends to be enlarged in size, particularly in a radial direction of the handle bar.
A throttle device is known wherein a cable type (mechanical type) transmission mechanism is provided for controlling the throttle opening by a turning torque on a throttle grip. A turning operation on the throttle grip is conducted at the time of a predetermined motive power control such as a constant vehicle speed maintaining control (auto cruise control). When an input to the transmission mechanism or the like by the turning operation is detected, the motive power control is cancelled. See, for example, Japanese Patent Laid-open No. 2001-246960.
In addition, a throttle device is known wherein a throttle grip is turnable between a throttle full-opening position and a beyond-throttle-full-closure position located beyond a throttle full-closing position. An engaging means is provided for controlling the turning of the throttle grip by engaging with the throttle grip between the throttle full-closing position and the beyond-throttle-full-closure position. A detection means is provided for detecting that the throttle grip has been turned to the beyond-throttle-full-closure position. A predetermined motive power control such as an idling-stopping control is conducted when the detection means has detected that the throttle grip is turned to the beyond-throttle-full-closure position. See, for example, Japanese Patent Laid-open No. 2005-147007.
In this case, the turning of the throttle grip toward the throttle-closing side is stopped by the engagement with the engaging means. From this condition the throttle grip is operated comparatively strongly so as to cancel the engagement, whereby it is made possible to turn the throttle grip to the beyond-throttle-full-closure position. Similarly, the cancellation of the engagement is needed also at the time of turning the throttle grip from the beyond-throttle-full-closure position toward the throttle-opening side.
Further, in the former of the above-mentioned configurations, it is necessary that detection means for detecting the turning of the throttle grip is provided at an intermediate part of the transmission mechanism or is connected through a transmission mechanism provided separately. Thus, a complicated configuration is necessary for detecting the turning of the throttle grip.
In addition, in the latter of the above-mentioned configurations, a comparatively strong operating force is needed at the time of turning the throttle grip from the throttle full-closing position to the beyond-throttle-full-closure position and at the time of returning the throttle grip from the beyond-throttle-full-closure position to the throttle full-closing position, so that the operation load necessary for a predetermined motive power control is high.